Obsidian hydration dating by infrared transmission spectroscopy

FERNANDO FRANCHETTI; GUSTAVO NEME; ADOLFO GIL; LAURA SALGÁN; ALEXANDER K. ROGERS; JAMES DAVENPORT; RAVEN GARVEY; OLGA TROFIMOVA; THEGN N. LADEFOGED; CHRISTOPHER M. STEVENSON

ARCHAEOMETRY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2024

0003-813X

The obsidian dating method converts the quantity of diffused molecular water within a near-surface hydration layer to elapsed time using an experimentally derived diffusion coefficient predicted from the structural water content of the glass. Infrared spectroscopic transmission measurements on transparent archaeological samples record vibrational responses of water bands in the near infrared region, permitting determination of structural water content (OH) and the amount of ambient diffused water (H2O). In this application the H2O water band at 5200cm-1 is measured directly. The accuracy of the approach is assessed by an evaluation of the precision of each contributing variable. The new protocol is evaluated using obsidian from radiocarbon dated deposits from Salamanca Cave in Argentina.